Apple Microarchitecture Research by Dougall Johnson

M1/A14 P-core (Firestorm): Overview | Base Instructions | SIMD and FP Instructions
M1/A14 E-core (Icestorm):  Overview | Base Instructions | SIMD and FP Instructions

FCVTNU (vector, 4S)

Test 1: uops

Code:

  fcvtnu v0.4s, v0.4s
  movi v0.16b, 1
  movi v1.16b, 2

(no loop instructions)

1000 unrolls and 1 iteration

Retires: 1.000

Issues: 1.000

Integer unit issues: 0.000

Load/store unit issues: 0.000

SIMD/FP unit issues: 1.000

retire uop (01)cycle (02)03091e3f4e51schedule uop (52)schedule simd uop (54)dispatch simd uop (57)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map simd uop (7e)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst simd alu (9a)l1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)f5f6f7f8fd
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110000373116112629100030383038303830383038
1004303723006125472510001000100039816013018303730372414328951000100010003037303711100110001073116112629100030383038303830383038
1004303724008225472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303724006125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037240010325472510001000100039816013022303730372414328951000100010003037303711100110000073116112629100030383038303830383038
10043037240012425472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723007825472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303724006125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038
1004303723006125472510001000100039816003018303730372414328951000100010003037303711100110000073116112629100030383038303830383038

Test 2: Latency 1->2

Code:

  fcvtnu v0.4s, v0.4s
  movi v0.16b, 1
  movi v1.16b, 2

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)03191e1f3f4e51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)accfd5map dispatch bubble (d6)ddfetch restart (de)e0? int output thing (e9)ea? simd retires (ee)? int retires (ef)f5f6f7f8fd
1020430037233000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116112963300100001003003830038300383003830038
102043003723301201382954725101001001000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116112963300100001003003830038300383003830038
1020430037232000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116112963300100001003003830038300383003830038
1020430037233000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116112963300100001003003830038300383003830038
10204300372320007262954725101001001000010010000500427716003001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116012963300100001003003830038300383003830038
1020430037232000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116112963300100001003003830038300383003830038
1020430037233000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116112963300100001003003830038300383003830038
1020430037233000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116112963300100001003003830038300383003830038
1020430037232000892954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116112963300100001003003830038300383003830038
1020430037232000612954725101001001000010010000500427716013001830037300372826432874510100200100002001000030037300371110201100991001001000010000710116112963300100001003003830038300383003830038

1000 unrolls and 10 iterations

Result (median cycles for code): 3.0037

retire uop (01)cycle (02)0318191e3f4e51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)acc2branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)d9ddfetch restart (de)e0? int output thing (e9)? simd retires (ee)? int retires (ef)f5f6f7f8fd
100243003723300186129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000064021602229629010000103003830038300383003830038
10024300372330006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000104000064021602229629010000103003830038300383003830038
10024300372330006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000064021602229629010000103003830038300383003830038
10024300372250006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000064021602229629010000103003830038300383003830038
10024300372250006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000064021602229629010000103003830038300383003830038
10024300372250006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000064021602229629010000103003830038300383003830038
10024300372250006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000064021602229629010000103003830038300383003830038
10024300372250006129547251001010100001010000504279864030018300373003728286328767103122010000201000030037300371110021109101010000100407500064021602229629310000103003830038300383003830038
10024300372250006129547251001010100001010000504277160030018300373017928286328767100102010000201000030037300371110021109101010000100000064021602229629010000103003830038300383003830038
10024300372250006129547251001010100001010000504277160030018300373003728286328767100102010000201000030037300371110021109101010000100000064021602229629010000103003830038300383003830085

Test 3: throughput

Count: 8

Code:

  fcvtnu v0.4s, v8.4s
  fcvtnu v1.4s, v8.4s
  fcvtnu v2.4s, v8.4s
  fcvtnu v3.4s, v8.4s
  fcvtnu v4.4s, v8.4s
  fcvtnu v5.4s, v8.4s
  fcvtnu v6.4s, v8.4s
  fcvtnu v7.4s, v8.4s
  movi v8.16b, 9

(fused SUBS/B.cc loop)

100 unrolls and 100 iterations

Result (median cycles for code divided by count): 0.2505

retire uop (01)cycle (02)03l2 tlb miss data (0b)1e3f51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696b6d6emap stall dispatch (70)simd prf full (72)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)acbranch cond mispred nonspec (c5)branch mispred nonspec (cb)cdcfd5map dispatch bubble (d6)ddfetch restart (de)e0? simd retires (ee)? int retires (ef)f5f6f7f8fd
802042005915501258258010810080008100800205006401321200200200392003999770699908012020080032200800322003920039118020110099100100800001000011151181160020036800001002004020040200402004020040
802042003915503330258010810080008100800205006401320200200200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391550030258010810080008100800205006401321200200200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391550030258010810080008100800205006401320200200200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391550030258010810080008100800205006401320200200200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
802042003915500695258010810080008100800205006401320200200200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391550030258010810080008100800205006401320200200200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
802042003915501530258010810080008100800205006401321200200200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040
80204200391550030258010810080008100800205006401320200200200392003999770699908012020080032200800322003920039118020110099100100800001001011151180160020036800001002004020040200402004020040
80204200391560030258010810080008100800205006401320200200200392003999770699908012020080032200800322003920039118020110099100100800001000011151180160020036800001002004020040200402004020040

1000 unrolls and 10 iterations

Result (median cycles for code divided by count): 0.2505

retire uop (01)cycle (02)03mmu table walk instruction (07)18191e1f3f51schedule uop (52)schedule int uop (53)schedule simd uop (54)dispatch int uop (56)dispatch simd uop (57)int uops in schedulers (59)ldst uops in schedulers (5b)60696d6emap stall dispatch (70)simd prf full (72)map rewind (75)map stall (76)dispatch uop (78)map int uop (7c)map simd uop (7e)map int uop inputs (7f)map simd uop inputs (81)8283flush restart other nonspec (84)85inst all (8c)inst branch (8d)inst branch taken (90)inst branch cond (94)inst int alu (97)inst simd alu (9a)9fl1d cache writeback (a8)accdcfd0d5map dispatch bubble (d6)ddfetch restart (de)e0ec? simd retires (ee)? int retires (ef)f5f6f7f8fd
800242005015500000692580010108000010800005064000002002020039200399996031001980010208000020800002003920039118002110910108000010000502003163320036080000102004020040200402004020040
800242003915600000402580010108000010800005064000012002020039200399996031001980010208000020800002003920039118002110910108000010000502003163320036080000102004020040200402004020040
800242003915500000402580010108000010800005064000002002020039200399996031001980010208000020800002003920039118002110910108000010000502003164320036080000102004020040200402004020040
800242003915500000402580010108000010800005064000012002020039200399996031001980010208000020800002003920039118002110910108000010000502003163220036080000102004020040200402004020040
800242003915500000402580010108000010800005064000002002020039200399996031001980010208000020800002003920039118002110910108000010000502002162320036080000102004020040200402004020040
800242003915500000402580010108000010800005064000012002020039200399996031001980010208000020800002003920039118002110910108000010030502003163220036080000102004020040200402004020040
8002420039155000150402580010108000010800005064000012002020039200399996031001980010208000020800002003920039118002110910108000010000502003163220036080000102004020040201122004020040
800242003915500000402580010108000010800005064000002002020039200399996031001980010208000020800002003920039118002110910108000010000502003163320036080000102004020040200402004020040
8002420039155000210402580010108000010800005064000002002020039200399996031001980010208000020800002003920039118002110910108000010000502003163320036080000102004020040200402004020040
800242003915600000402580010108000010800005064000002002020039200399996031001980010208000020800002003920039118002110910108000010000502002163220036080000102004020040200402004020040